QUAD ESL-989 User manual

Brand: QUAD

Model: ESL-989

Category: Soundbar speakers

Type: User manual

This manual is also suitable for

Classic Series ESL

...the closest approach to the original sound

ELECTROSTATIC LOUDSPEAKERS

The Quad ESL is fundamentally different from

conventional loudspeakers and even other electrostatic

designs. Whilst most conventional speakers use cone

type drive units and a coil moving in a magnetic field,

Quad uses the full-range electrostatic principle, first

introduced in 1956. The sound is not created by a

cone but by a very thin diaphragm, less than one tenth

the thickness of a human hair. This ultra-low mass

diaphragm is coated with a conductive material and is

stretched between two fixed electrode plates. The

electrodes carry a positive charge and the diaphragm

carries a negative charge. The size of the charge on the

electrodes rises and falls to track the waveform of the

musical signal; so attracting and repelling the

diaphragm closer to and further from the electrode

plates. It is the movement of the almost mass-less

diaphragm that creates the sound we hear.

Quad’s unique ESL system takes the performance of

electrostatic loudspeakers a step further. Acousticians

have long recognised that the ideal loudspeaker

should be a point source from which the waves of

sound radiate in a fashion rather like the ripples

resulting from a pebble dropped into a lake. It is

obvious that large cones and even larger electrostatic

diaphragms cannot be point sources, so how can they

be made to behave more like the perfect loudspeaker?

Quad solved the problem with an elegant engineering

solution that was subsequently awarded a patent.

Instead of a large single electrode, Quad designed a

number of electrodes arranged as a series of

concentric rings. Each electrode is fed with a calibrated

delay line so the sound first leaves the centre of the

speaker then, after a short delay, the sound leaves the

next ring and so on. The delayed sounds build up into

a spherical waveform identical to that produced by a

theoretical point source. This innovative step brought

closer the achievement of the perfect loudspeaker.

The Quad ESL is a premiére music reproduction

loudspeaker constructed from the finest materials with

meticulous attention to detail. It reaches the pinnacle

of high-fidelity performance with an unparalleled

ability to sonically ‘disappear’, and create convincing

three-dimensional sound stages. Instruments and

vocals occupy precise, accurately sized locations in

space, giving an uncanny realism to reproduced

sound.

The Quad

A legend in Electrostatic loudspeaker design

ESL

‘Even if price weren’t an issue I’d be hard pushed

to find speakers that better the 988s’ combination

of talents... I can’t recommend them too highly’

Gramophone (March 2001)

There are few things in life as rewarding as a truly

invigorating live performance from our favourite artist

or orchestra.

Reproducing that experience accurately in the home

requires loudspeakers that go beyond the conventional.

To really understand the ESL, a listener needs to be

familiar with the nature of a live performance. Whilst the

performance may be impressive and communicate all

kinds of emotions, it is never artificial. It sounds real

and natural.

At Quad, we believe this is the job of a loudspeaker.

To present the music in the raw, natural form -

nothing added, nothing taken away. In this respect,

the ESL is an acquired taste. It displays none of the

over-empasized bass boom or mid-range projection

that plagues moving-coil, box-bound speakers - so in

comparison, the ESL can seem rather meek and polite.

The characteristics, however, that can make these box

speakers so impressive, are also those that cause

fatigue and wear down the listener. Spend some time

with the ESL and you too will begin to realise that it’s

not always the one that shouts the loudest that gets

heard.

It is often said of ‘box’ or cabinet mounted loudspeakers

that you can hear more of the box than the driver. This

is true, even with high-end ‘box’ loudspeakers. The box

- no matter how inert - will always colour the sound.

Electrostatic loudspeakers are therefore in a league of

their own in terms of ‘transparency’.

But to get really close to the original sound, a standard

planar electrostatic speaker, needs more. At a live

performance, each sound comes from an identifiable

position on the stage. To reproduce this three-

dimensional sound ‘image’ accurately, we need to

produce an interference pattern upon the listener of

waves propagated from a pair of true point sources - in

much the same way as a laser produces a hologram.

The Quad ESL 988 and 989 speakers are the only

electrostatic speakers in the world to effectively mimic a

point-source.

Five minutes spent listening to a well set-up pair of

Quad ESLs will confirm their ability to project the

positions of each and every vocalist in a choir, and

instrument in an orchestra - with a naturalness and level

of detail that makes the Quad ESL totally unique in

every respect.

‘Quads can deliver a sublime

performance. They still take my breath

away with their profound revelation’

– Hi-Fi World , Noel Keywood

The closest approach...

Ask many of the finest recording professionals in the

world what their speaker of choice is as the answer is

surprisingly common. The Quad ESL opens a window

on a recording unlike any other speaker.

For professional musicians and studios, this is an

invaluable asset, for no matter how good a moving coil

loudspeaker may seem - no matter how impressive its

dynamic ability, the laws of physics are such that it

cannot be as fast and accurate as an electrostatic

transducer. An ESL is like a giant capacitor, tracking the

music signal with such precision and agility that using

them is the only real way to know exactly what is on the

recording.

The Quad ESL has been used by Tony Faulkner for many

years. He use the ESL 63, the ESL 63 Pro and now uses a

pair of ESL 989s for his critical monitoring.

Tony has produced over a thousand classical music

recordings using the Quad ESL because he knows he

can trust what he hears - that the very essence of the

performance is being transferred.

Likewise with acoustic engineers - what do they regard

as an absolute reference? Next time you are visiting a hi-

fi show, look for the acoustic engineers - the amplifier

designers - even the other loudspeaker designers. More

likely than not, they will have a pair of ESLs hidden

away in a corner.

Lastly consider the magazine reviewers - the so-called

critics with golden ears who listen daily to a multitude

of loudspeakers - assessing how they perform. What do

they use to compare all other speakers?

Once again, the results are clear. Although arguments

rage between them - Ken Kessler, Senior Reviewer at Hi-

Fi News Magazine awarded the ESL-57 ‘Product of the

Millennium’ back in 2000 and in his mind it has never

been surpassed. Paul Seydor, Hollywood editor and the

man in charge of the absolute sound waxes lyrical about

the ESL 63 at every opportunity, whilst Stereophile

magazine has awarded the ESL 989, not only Product of

the Year in 2004, but Component of the Year as well -

the highest of all awards. The real answer is that Quad

ESLs have always been in a class of their own, each

generation winning new fans and enthusiasts.

‘Going back to conventional speakers

afterwards merely highlights how great

the 989 is’ – Hi-Fi News (July 2000)

The closest approach...

‘When I return the 988s it will

be in a package much too small

for the speakers, but just large

enough to carry a check for

their remittance.’

– The Absolute Sound (July 2001)

‘The Best Late Night Speakers in

The World...ever!’

– Hi-Fi World (December 2000)

After a number of years producing just a

single colour version of the ESL 988 and

ESL 989speakers, we decided to offer our

customers a couple of new alternatives.

Picture here is the ‘vintage’ finish, with

wooden top and base caps and an

classical style cloth ‘sock’

ESL 989 vintage

The ESL-988 replaces the much-loved ESL-63 model.

Although of similar size and proportions, the

resemblance is only skin deep – for more than 90% of

the internal components have been re-designed,

upgraded, or modified. Twenty years of materials

science have led to improvements in virtually every

component and area of construction.

The new model has better audio transformers, a new

power supply, improved diaphragms, a strong

heavyweight moulded base and new grille assemblies.

Particular attention has been given to the structural

integrity of the loudspeakers, which has been improved

beyond all recognition.

The result of these changes is an electrostatic

loudspeaker that is as much a leader today as its

predecessor was 20 years ago. Larger dynamics and a

smoother response are two of the most noticeable

improvements in sound quality. A slight backward tilt

lifts the stereo image when these speakers are floor

standing.

The ESL-989 shares much of its technology with the ESL-

988, but it is a larger model with two extra bass panels

and a higher rated power supply. The extra panels

increase the bass output, but also contribute to an

enhanced performance in the mid-band, which was

already widely regarded as the cleanest in the world.

Although referred to as ‘bass panels’, the additional

electrostatic panels are, in fact, full range (as are all the

panels), but the increase in surface area allows a greater

volume of air to be moved, leading to an improvement

in the lower frequencies. This particular development

had been anticipated for many years, but was never

previously regarded as commercially and practically

viable.

The ESL-989 is Quad’s finest loudspeaker. It is a true full

range electrostatic loudspeaker reproducing music with

an ease and naturalness that is best described as

uncanny. It has a virtual absence of the familiar

loudspeaker problems of colouration, distortion, phase

and frequency response errors. All that remains is the

music and the original ambience. To the listener these

are the very ingredients needed to create a real

sensation of being there.

The Quad electrostatic loudspeakers are unique and

continue to be in a class of their own, but now have the

versatility and range to cope with a much wider

repertoire.

ESL 988

ESL 989

‘Quad has done it again: the

988s are world class - the single

driver presents a fabulously

together sound that’s tough to

match at any price’

– What Hi-Fi? (December 2000)

Maximum Power Output

Sensitivity

Impedance

Maximum continuous input voltage

Programme peak ( 20 Hz to 20 kHz )

For undistorted output

Permitted peak input

Directivity index

Axis band limits

( low level )

AC Input

( double insulated )

Dimensions ( H x W x D )

(including 185mm base)

Weight

2N/m2 at 2m on axis

1.5u bar per volt referred to 1m (86dB/2.83V RMS)

8 ohm nominal

10V

40V

55V

125Hz . . . . . .5.0dB

500Hz . . . . . .6.4dB

1kHz . . . . . . . .7.2dB

8kHz . . . . . . .10.6dB

-6dB at 35Hz 3rd order

-6dB > 20kHz

220-240V or 110-120V

See rating details on base of unit

940mm x 670mm x 315mm

(including 185mm base)

20.5kg net

Vintage & Nouveau

Both our international award-winning ESL

loudspeakers are now available for the first time in a

choice of colours and finishes. Whilst for some

audiophiles such details are of trifling importance,

Quad recognise that for many, the ESL needs to vanish

into it's surroundings visually as well as audibly –

whether these surroundings be a stately home or

docklands apartment.

The original black-on-black finish is now

complemented with the ‘Vintage’ and the ‘Nouveau’

finishes. Sonically, these are identical to the standard

model, but aesthetically, they offer more variety. The

Vintage models include a wooden base-plate, as well as

the wooden top-cap, reminiscent of the older ESL-63

and a woven – yet acoustically transparent sock as an

alternative to black. The Nouveau model has a brushed

metal top-cap and co-ordinated base to complement

the light blue colour of the cloth.

Specifications

Model ESL 988 ESL 989

2N/m2 at 2m on axis

1.5u bar per volt referred to 1m (86dB/2.83V RMS)

8 ohm nominal

10V

40V

55V

125Hz . . . . . .5.0dB

500Hz . . . . . .6.4dB

1kHz . . . . . . . .7.2dB

8kHz . . . . . . .10.6dB

-6dB at 35Hz 3rd order

-6dB > 20kHz

220-240V or 110-120V

See rating details on base of unit

1335mm x 670mm x 315mm

(including 185mm base)

25.3kg net

Vintage Nouveau

Quad Electroacoustics Ltd, IAG House, Sovereign Court, Ermine Business Park, Huntingdon, PE29 6XU

Tel :- 0845 4580011, Fax :- 01480 431767

www.quad-hifi.co.uk

The information in this brochure is subject to change without notice.

Quad is a member of the International Audio Group

Qu.ESL 25.10.2004

QUAD ESL-989 User manual

Brand: QUAD

Model: ESL-989

Category: Soundbar speakers

Type: User manual

This manual is also suitable for

Classic Series ESL

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QUAD ESL-989 User manual

This manual is also suitable for

QUAD ESL-989 User manual

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